Written by: Samantha Walker
Some of the physical and behavioral similarities between domesticated animals and their wild brethren make it easy to see they share a common ancestor. But then again, how can domestication account for such astounding and apparent differences within a biological family? Why is a Pomeranian so small and fluffy whereas wolves and coyotes have larger, leaner builds? More to the point, why are domesticated animals so docile compared with their wild counterparts?
In an article published in the July issue of Animal Frontiers, Alan Beck from the Center for the Human–Animal Bond at Purdue University writes about the biology behind the appearances and behaviors of our domesticated companions.
The article, entitled “The biology of the human-animal bond,” begins by explaining the concept of neoteny. Neoteny is the “retention of juvenile physical attributes through maturity.”
This includes traits such as smaller teeth, shorter snouts, larger eyes, etc. In the article, Beck explains how selection for more docile behavioral traits goes hand in hand with the retention of juvenile physical traits.
“In the 1960s, Dmitry Belaev and Lyudmila Trut* showed that if you keep breeding foxes for tameness, you soon develop a fox that has the morphology and behavior of the domestic dog,” Beck wrote. “For each generation, they simply selected foxes that exhibited little aggression and acceptance of human touch. By the 10th generation, 18 percent of fox pups were totally tame. After 15 to 20 generations, the foxes exhibited the shorter snouts and coat patterns of domestic dogs, and 35 percent were tame.”
The article also covers theories on the psychological and chemical changes associated with domestication.
For example, oxytocin, commonly referred to as the bonding hormone, the love hormone or the feel good hormone, was found in higher concentrations in the tamed foxes than in the non-tame controls.
These results, and results from similar studies, provide evidence for a social support theory that people receive physical and emotional support from relationships with their furry friends and vice versa.
“Domestication has changed our relationship with animals, and perhaps also not surprisingly, it has changed the relationship of animals with people,” Beck wrote.
Animal Frontiers is a joint venture between four globally active professional animal science societies: American Society of Animal Science (ASAS), Canadian Society of Animal Science (CSAS), the European Federation of Animal Science (EAAP), and the American Meat Science Association (AMSA). Each issue of Animal Frontiers consists of a series of invited, peer-reviewed articles that present several international perspectives on the status of a high-impact, global issue in animal agriculture today.
*For more on the Farm-Fox Experiment, see:
American Scientist: http://www.americanscientist.org/issues/feature/early-canid-domestication-the-farm-fox-experiment/1 (last accessed 05-July-14); and
National Geographic: http://ngm.nationalgeographic.com/print/2011/03/taming-wild-animals/ratliff-text (last accessed 05-July-14).
ASAS Media Communications
ASAS Media Communications